|Publication number||US7491978 B2|
|Application number||US 11/492,754|
|Publication date||Feb 17, 2009|
|Filing date||Jul 26, 2006|
|Priority date||Jul 26, 2005|
|Also published as||US20070023776|
|Publication number||11492754, 492754, US 7491978 B2, US 7491978B2, US-B2-7491978, US7491978 B2, US7491978B2|
|Inventors||Alexander L'Vovich Zakgeym, Seog Moon Choi, Sung Jun Lee|
|Original Assignee||Samsung Electro-Mechanics Co., Ltd.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (3), Referenced by (4), Classifications (6), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application claims the benefit of Russian Patent Application No. 2005123795 filed on Jul. 26, 2005 in the Russian Patent Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a light emitting diode package, and, more particularly, to a high power light emitting diode package, which overcomes a problem of defects in a metal wiring structure caused by a step of a submount substrate.
2. Description of the Related Art
Generally, light emitting packages must satisfy two requirements, namely, high light emitting efficiency and excellent heat dissipation. These characteristics are very important, in particular, for high power light emitting diode packages mainly used in illuminating apparatuses.
In view of the light emitting efficiency and heat dissipation, a conventional light emitting diode employs a package which comprises a semiconductor substrate such as silicon having a cavity formed therein, as a submount substrate. One example of the light emitting diode is illustrated in
As shown in
As shown in
Although silicon mainly used for the submount substrate 11 has a low thermal conductivity about a third of that of metal, it can be machined to a narrow thickness through a MEMS process, thereby ensuring a lower thermal resistance. Moreover, the mounting region has a structure wherein, after the cavity C is formed on the submount substrate 11 by typical semiconductor processing, metal reflecting plates 16 are formed at opposite sides of the cavity C. The package 10 having the metal reflecting plates 16 ensures high light emitting efficiency.
However, the conventional light emitting diode package 10 suffers defects in the wiring structure due to formation of the cavity C provided as the mounting region. That is, since the first and second conductive lines 14 a and 14 b are formed along inclined side walls of the cavity C, respectively, there is a high possibility of disconnection at portions (regions indicated by I and II) where the first and second bump pads 13 a and 13 b are connected to the first and second bonding pads 15 a and 15 b, respectively.
As such, the submount substrate having the cavity formed in the mounting region provides advantages in view of easy formation of the reflecting plates for enhancing the light emitting efficiency, and effective thermal dissipation by a small thickness of the portion of the substrate where the light emitting diode is mounted. However, since steps are formed on the submount substrate due to formation of the cavity, and cause disconnection, there is a limitation in manufacturing of a highly reliable light emitting diode package with such a submount substrate.
The present invention has been made in view of the above problems, and it is an object of the present invention to provide a light emitting diode package, which lowers a height of steps or removes the steps from a region to be formed with a wiring structure, thereby preventing undesired disconnection in the wiring structure.
In accordance with one aspect of the present invention, the above and other objects can be accomplished by the provision of a light emitting diode package, comprising: a submount substrate including a mounting region having side walls inclined upwardly, first and second cavities formed around the mounting region, and first and second grooves extending between the mounting region and the first and second cavities on an upper surface of the submount; first and second bump pads formed on a bottom surface of the mounting surface; first and second bonding pads formed on a bottom surface of the first and second cavities, respectively; first and second conductive lines formed along a bottom surface of the first and second grooves for connecting the first and second bump pads to the first and second bonding pads, respectively; and a light emitting diode mounted on the mounting region so as to be connected to the first and second bump pads.
The light emitting diode package may further comprise reflecting plates formed on the side walls. The submount substrate may be a silicon substrate having an insulating layer formed on an upper surface thereof. In this case, the insulating layer may be a SiO2 layer formed by a thermal oxidation process.
The first and second cavities, the mounting regions, and the first and second grooves may be formed to have substantially coplanar bottom surfaces. As a result, the first and second conductive lines can be formed on the substantially coplanar bottom surface.
The mounting region may be located at a center of the upper surface of the submount substrate, and the first and second cavities may be located at opposite sides of the mounting region. The first and second cavities, the first and second grooves, and the mounting region may be integrated to a single cavity region having a predetermined width.
At least one of the first and second cavities may be opened at one side through a side of the submount substrate. In this manner, wire bonding between the bonding pads formed on the first and second cavities and the external circuit can be easily performed.
The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
The light emitting diode package 20 of
As shown in
As shown in
The first and second bump pads 23 a and 23 b are connected to the bonding pads 25 a and 25 b via first and second conductive lines 24 a and 24 b formed on the bottom surface of the grooves P12 and P13. Unlike the conventional light emitting diode package (see
As such, the present invention is characterized in that the steps are lowered in height or removed altogether from the wiring region by an additional etching process to the region where the bonding pads and the conductive lines will be formed, thereby providing a highly reliably light emitting diode package.
Unlike the structure shown in
A light emitting diode package 30 shown in
According to the present embodiment, reflecting layers 36 on opposite side walls of the cavity C can be formed on opposite side walls adjacent to a light emitting diode 38. Thus, although the package of the embodiment is relatively low in enhancement of light emitting efficiency, it can be manufactured via a more simple process.
As shown in
The present embodiment provides advantages in that an area for the reflecting layers 46 can be similar to that shown in
In the present embodiment, the first and second cavities D1 and D2, and the grooves P12 and P13 are formed to have the substantially same depth as that of the main cavity C1 in the mounting region, thereby allowing the first and second conductive lines 44 a and 44 b to be formed on the substantially flat surface as shown in
As apparent from the description, according to the present invention, the steps are lowered in height or removed altogether from the wiring region by an additional etching process to the region where the bonding pads and the conductive lines will be formed together with a cavity provided as a mounting region and having side walls for forming reflecting layers, thereby providing a highly reliably light emitting diode package which can prevent undesired disconnection of the wiring.
It should be understood that the embodiments and the accompanying drawings have been described for illustrative purposes and the present invention is limited only by the following claims. Further, those skilled in the art will appreciate that various modifications, additions and substitutions are allowed without departing from the scope and spirit of the invention according to the accompanying claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US6838689 *||Sep 25, 2002||Jan 4, 2005||Finisar Corporation||Backside alignment and packaging of opto-electronic devices|
|US6881980 *||Jun 17, 2004||Apr 19, 2005||Chunghwa Picture Tubes, Ltd.||Package structure of light emitting diode|
|US20050087866 *||Apr 16, 2004||Apr 28, 2005||Shih-Chang Shei||Flip-chip light emitting diode package structure|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US8530920 *||Apr 13, 2011||Sep 10, 2013||Sunonwealth Electric Machine Industry Co., Ltd.||Packaging structure for plural bare chips|
|US9064773 *||Mar 15, 2013||Jun 23, 2015||Lg Innotek Co., Ltd.||Light emitting device package|
|US20120224366 *||Apr 13, 2011||Sep 6, 2012||Chong-Han Tsai||Packaging Structure for Plural Bare Chips|
|US20140117357 *||Mar 15, 2013||May 1, 2014||Lg Innotek Co., Ltd.||Light emitting device package|
|U.S. Classification||257/98, 257/E33.056|
|Cooperative Classification||H01L33/62, H01L2224/16|
|Jul 26, 2006||AS||Assignment|
Owner name: SAMSUNG ELECTRO-MECHANICS CO., LTD., KOREA, REPUBL
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ZAKGEYM, ALEXANDER L VOVICH;CHOI, SEOG MOON;LEE, SUNG JUN;REEL/FRAME:018092/0753;SIGNING DATES FROM 20060711 TO 20060720
|Jul 22, 2010||AS||Assignment|
Owner name: SAMSUNG LED CO., LTD., KOREA, REPUBLIC OF
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SAMSUNG ELECTRO-MECHANICS CO., LTD.;REEL/FRAME:024723/0532
Effective date: 20100712
|Jul 25, 2012||FPAY||Fee payment|
Year of fee payment: 4
|Aug 7, 2012||AS||Assignment|
Owner name: SAMSUNG ELECTRONICS CO., LTD., KOREA, REPUBLIC OF
Free format text: MERGER;ASSIGNOR:SAMSUNG LED CO., LTD.;REEL/FRAME:028744/0272
Effective date: 20120403